Hydrated Fuel Production Method And Production Apparatus

ABSTRACT

Water-added fuel production method comprising: a water activation step of applying an electrical stimulation to water by means of high-voltage application or the like, to thereby activate molecules of the water; a stirring and mixing step of mixing the water in a state after undergoing the water activation step and in which at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution is added as an additive thereto, with the raw fuel oil, and stirring the resulting mixture; and a fusion step of fusing the raw fuel oil and the water during the stirring and mixing step or after undergoing the stirring and mixing step, together under a high temperature and a high pressure.

TECHNICAL FIELD

The present invention relates to a method and an apparatus for producing a water-added fuel by adding water to fuel oil.

BACKGROUND ART

Recently, it has been some time since environmental problems became an important issue on a global basis, and, as one countermeasure, technical developments regarding solar power generation, wind power generation and the like have been actively conducted. However, before achievement of full transition to such renewable energy, it is necessary to meticulously use traditional fossil fuel involved with a depletion problem, and conduct technical developments from many angles, such as developments regarding internal combustion engines and burning plants/facilities having less energy loss, and improvement of fossil fuel itself in terms of a calorific property or a combustion property, in a parallel manner. As one of them, a technique of mixing water to fuel oil has been developed.

A water-added fuel, i.e., fuel produced by mixing water to fuel oil, is regarded as an environmentally-superior fuel, because it is capable of significantly reducing an amount of fuel oil to be used, and reducing carbon dioxide (CO₂) emission by an amount corresponding to the reduction in amount of fuel oil used. Further, complete combustion can be expected, so that it is possible to fairly reduce an amount of air to be used for combustion. As a result, there is an advantage effect of being able to suppress generation of nitrogen oxides and particulate matter (PM), and reduce an environmental load due to emission gas from boilers or internal combustion engines.

As above, the water-added fuel is highly useful. On the other hand, generally, water and oil have difficulty in being perfectly fused together, and tend to be separated from each other after the elapse of a certain time even when they were fully blended or mixed together. Although it is not impossible to sufficiently fuse water and oil together using a conventional technique, it requires taking so much time. Thus, it is assumed that such a conventional technique is far from practical use from an economic viewpoint.

Therefore, there is a need for a technique capable of perfectly fusing water and fuel oil together, within a relatively short period of time, so as to produce a water-added fuel free from separation even after the elapse of a certain time since the fusion.

As one technique for improving combustion efficiency of a chemical fuel, heretofore, a technique regarding a water-added fuel which is produced by mixing fuel oil and water in the presence of a surfactant (the following Patent Document 1) has been proposed and known as a publicly known technique. More specifically, the Patent Document 1 discloses a method comprising: bringing a natural ore into contact with a mixture of fuel oil (raw fuel oil) and water to which oxygen is added, and simultaneously stirring and mixing the mixture while applying ultrasonic vibration thereto; and further heating the mixture of the fuel oil and the water after being stirred and mixed, to 30° C. to 150° C., and pressurizing the mixture to 3 atm to 10 atm, and describes that this method makes it possible to obtain a water-added fuel in an emulsified state. The Patent Document 1 also describes that this production method makes it possible to prevent an oil-water separation phenomenon in an emulsion fuel having a water addition rate of 50% or more.

However, in this production method, an emulsion fuel to be obtained has a composition containing water (H₂O), so that there is a limit in terms of a period of time in which the oil-water separation phenomenon can be prevented. Thus, the oil-water separation phenomenon is likely to occur after the elapse of 2 or 3 months. Moreover, the degree of transparency of the water-added fuel tends to become lower than that of the fuel oil. Therefore, the water-added fuel production method taught by the Patent Document 1 is not a satisfactory technique as a solution to the aforementioned problem.

CITATION LIST Patent Document

-   Patent Document 1: JP 4682287B

SUMMARY OF INVENTION Technical Problem

With a focus on the above conventional problems, it is a primary problem of the present invention to provide a water-added fuel production method and a water-added fuel production apparatus capable of solving all of the problems.

It is another object of the present invention to provide a water-added fuel production method and a water-added fuel production apparatus capable of producing a water-added fuel which has a composition and physical properties substantially identical to or approximate to those of raw fuel oil, i.e., fuel before addition of water, and exhibits properties equal to those of the raw fuel oil in terms of oil-water separation.

Solution to Technical Problem

According to one aspect of the present invention, there is provided a water-added fuel production method comprising at least: a water activation step of applying an electrical stimulus to water by means of high-voltage application or the like to thereby activate molecules of the water; a stirring and mixing step of mixing the water in a state after undergoing the water activation step and in which at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution is added as an additive thereto, with the raw fuel oil, and stirring the resulting mixture; and a fusion step of fusing the raw fuel oil and the water during the stirring and mixing step or after undergoing the stirring and mixing step, together under a high temperature and a high pressure. The term “activate molecules of the water” herein means that molecules of the water reach a state in which they are more likely to develop a required reaction in the stirring and mixing step and the fusion step.

A water-added fuel produced by the method of the present invention is substantially free of water (H₂O) and has a composition and physical properties substantially identical to or approximate to those of the raw fuel oil. For example, in the case where the raw fuel oil is light oil to be used as a diesel fuel, it is possible to obtain a remarkable result that the resulting water-added fuel is formed as light oil equivalent to the light oil as the raw fuel oil. The light oil produced by the present invention is substantially free of water (H₂O), and it has been ascertained that no oil-water separation occurs even when it is stored over a long period of time.

Similarly, in the case where the raw fuel oil is A-heavy oil, the method of the present invention makes it possible to produce heavy oil substantially equal to or approximate to A-heavy oil.

As above, despite the addition of the water to the raw fuel oil, the resulting water-added fuel is substantially free of water (H₂O) and has a composition and physical properties substantially identical to or approximate to those of the raw fuel oil. For achieving this, it is necessary to take in, from outside, carbon for creating hydrocarbon as a combustible component. Although it is not intended to stick to a particular theory, in the method of the present invention, it is assumed that carbon dioxide in surrounding air is taken in through a liquid surface of the mixture of the raw fuel oil and the water, and decomposed to obtain at least a large part of carbon necessary for a reaction for producing the water-added fuel. In the case where a surrounding area of a site for performing the stirring and mixing step is a closed space, an amount of carbon dioxide to be taken in from surrounding air becomes insufficient. In this situation, it has been ascertained that an intended water-added fuel can be obtained by adding carbon to the mixture of the raw fuel oil and the water.

It is also assumed that hydrogen necessary for creating hydrocarbon as a combustible component is obtained by decomposition of molecules of the water. In the method of the present invention, molecules of the water are activated by an electrical stimulus applied thereto. It has been ascertained that hydrogen necessary for the reaction can be obtained by adding at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution, to the water having such activated molecules, and stirring the resulting mixture.

It is considered that there is no particular limit in terms of an amount of the water to be added to the raw fuel oil. However, if an amount of the water to be added to the raw fuel oil is excessively increased, concern arises that practicality becomes impaired due to an excessively extended reaction time necessary for producing a water-added fuel having a desired composition. The inventor of the present invention has ascertained that, even in the case where the water is mixed with the raw fuel oil, in a ratio by volume of about 1 with respect of 1 of the raw fuel oil. When the ratio of the water to be added is less than the above value, a desired result can be obtained within a shorter period of time. Thus, preferably, in the method of the present invention, a mixing ratio by volume of the water to the raw fuel oil is set to about 1 or less with respect to 1 of raw fuel oil

Preferably, in the method of the present invention, the stirring and mixing step includes: inputting only the raw fuel oil into a stirring and mixing tank; and then adding and mixing the water after undergoing the water activation step and the additive input step, to and with the raw fuel oil in increments of a given amount, while stirring the raw fuel oil. In this case, the mixture is intensely stirred to create strong waves on a liquid surface. This advantageously enables carbon dioxide in air to be taken in the mixture.

Preferably, the method of the present invention is implemented using an apparatus comprising: a stirring and mixing tank having a cylindrical portion; and at least one injection pipe for inputting the water after undergoing the water activation step and the additive input step, into the stirring and mixing tank, in the form of a jet flow, wherein an injection direction of the water from the injection pipe is set to have a given angle with respect to a diametrical line of the cylindrical portion.

In the above embodiment using the apparatus comprising the at least one injection pipe attached to the cylindrical portion of the stirring and mixing tank, the given angle is preferably in the range of about 40 degrees to about 50 degrees, particularly about 45 degrees. In the case where the stirring and mixing tank is provided with a plurality of the injection pipes, the given angle in each of the injection pipes is preferably set to a specific angle, e.g., about 45 degrees, falling within the range of about 40 degrees to about 50 degrees. From a viewpoint of creating strong waves on the liquid surface in the stirring and mixing tank as mentioned above, an injection port of the injection pipe is preferably disposed at a position upwardly away from the liquid surface by at least about 8 cm, preferably 10 cm or more, to inject the activated water onto the liquid surface in the form of a high-speed jet.

Preferably, in the above embodiment, the injection pipe has a protruding portion protruding inside the stirring and mixing tank.

In this case, the protruding portion preferably has a length of about 10 cm.

In one preferred embodiment of the present invention, the additive input step includes adding catalase in a ratio by weight thereof to the water of 0.04 to 0.05%.

In another preferred embodiment of the present invention, the water activation step includes activating the water such that an ORP (Oxidation-Reduction Potential) value thereof falls within the range of 160 mV to −200 mV.

In yet another preferred embodiment of the present invention, the water activation step includes: keeping tourmaline or a copper ion generating material in contact with the water; and, in this state, irradiating the water, or the tourmaline or the copper ion generating material, alternately with first and second ultrasonic waves each having a respective one of a frequency of 10 kHz to 60 kHz and a frequency of 200 kHz or more, thereby activating the water by electrical energy radiated from the tourmaline or copper ions radiated from the copper ion generating material.

In still another preferred embodiment of the present invention, the fusion step is performed under a pressurization condition set at about 0.3 Mpa or more and a heating condition set in the range of about 40° C. to about 80° C.

In yet still another preferred embodiment of the present invention, the stirring and mixing step is performed using an OHR (Original Hydrodynamic Reaction) mixer.

According to another aspect of the present invention, there is provided an apparatus for producing a water-added fuel by mixing fuel oil and water together. The apparatus comprises: a water activation device for applying an electrical stimulus to water to thereby activate the water; an additive injection device for adding, as an additive, at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution, to the water; a stirring and mixing device for mixing the water after passing through the water activation device and the additive input device, with raw fuel oil, and stirring the resulting mixture; and a fusion device for fusing the raw fuel oil and the water after passing through the stirring and mixing device, together under a high temperature and a high pressure.

In the apparatus of the present invention, the water activation device may comprise an ultrasonic generator.

Preferably, the water activation device comprises a section for housing a catalyst, wherein the catalyst is tourmaline.

Alternatively, the water activation device may comprise a plasma-arc water treatment unit.

In this case, it is preferable that the water activation device comprises a section for housing a catalyst, wherein the catalyst is aluminum.

In the apparatus of the present invention, the stirring and mixing device may comprise an open-type stirring and mixing tank opened to the atmosphere.

Preferably, this stirring and mixing device comprises an injection pipe for injecting a liquid to be stirred and mixed, into the stirring and mixing tank, wherein the injection pipe is disposed at a position upwardly away from a liquid surface in the stirring and mixing tank by at least about 8 cm, more preferably at least 10 cm.

In the apparatus of the present invention, the fusion device comprises an OHR mixer.

Effect of Invention

In the present invention, based on the features of the above method and apparatus, it becomes possible to obtain a water-added fuel which is less likely to cause or free from causing oil-water separation after being synthesized or fused once. In addition, it becomes possible to efficiently produce the water-added fuel. The water-added fuel produced by the method and apparatus of the present invention is substantially free of water (H₂O) and has a composition and physical properties substantially identical to or approximate to those of the raw fuel oil, as mentioned above.

Further, the water-added fuel of the present invention is equal to or superior to existing fuel oils, in terms of a calorific value per unit quantum, and has an advantageous effect of being less likely to cause degradation or corrosion of a combustion chamber, an exhaust pipe or the like after combustion, as compared to the existing fuel oils. Furthermore, the water-added fuel of the present invention can achieve advantageous effects of: being excellent in perfect combustibility; being less likely to generate carbon monoxide; and being low in amount of emission of carbon monoxide.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a process chart of a water-added fuel production method according to one embodiment of the present invention.

FIG. 2 is a diagram depicting an overall configuration of a production apparatus according to a first embodiment of the present invention, for used in the water-added fuel production method according to the one embodiment.

FIG. 3 is a diagram depicting the structure of an injection pipe for injection to a reaction tank of a stirring device usable in a water-added fuel production apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram depicting one example of an ionization device usable in a water-added fuel production apparatus according to a third embodiment of the present invention.

FIG. 5 is a chart presenting a result of GC-MS analysis regarding a water-added fuel obtained by the method according to the present invention using light oil as raw fuel oil.

FIG. 6 is a chart presenting a result of GC-MS analysis regarding another water-added fuel obtained by the method according to the present invention using light oil as raw fuel oil.

FIG. 7 is a chart presenting a result of GC-MS analysis regarding the light oil used as raw fuel oil.

FIG. 8 is a chart presenting a result of GC-MS analysis regarding yet another water-added fuel obtained by the method according to the present invention using A-heavy oil as raw fuel oil.

FIG. 9 is a chart presenting a result of GC-MS analysis regarding the A-heavy oil used as raw fuel oil.

DESCRIPTION OF EMBODIMENTS

With reference to the drawings, a water-added fuel production method of the present invention will now be described based on an embodiment thereof.

It should be noted that an overall configuration, individual detailed configurations and numerical values in a water-added fuel production method described in the following embodiments and examples are not meant to be construed in a limiting sense, but various changes and modifications may be made therein within the spirit and scope of the present invention, i.e., within configurations and dimensions capable of fulfilling the same function.

Some embodiments of the present invention will be described based on FIGS. 1, 2 and 3. FIG. 1 is a flowchart of a process regarding a water-added fuel production method according to one embodiment of the present invention to be performed using a water-added fuel production apparatus according to the present invention. FIG. 2 is a diagram depicting an overall configuration of a water-added fuel production apparatus according to a first embodiment of the present invention, for used in the water-added fuel production method according to the one embodiment, and FIG. 3 is a diagram depicting the structure of an injection pipe for performing water injection to a reaction tank in a water-added fuel production apparatus according to a second embodiment of the present invention.

The water-added fuel production apparatus 1 according to the first embodiment comprises a raw fuel oil improving tank 2, a refined water tank 3, a reaction accelerator injection unit 4, a reaction tank 5, an improved oil statically-storing tank 6, and a product receiving tank 7. This apparatus 1 can be outlined as follows: Raw fuel oil is preprocessed in the raw fuel oil improving tank 2, and water is activated in the refined water tank 3. Then, after inputting an additive from the reaction accelerator injection unit 4 into a given tank, the raw fuel oil and the water are stirred, mixed and fused in the reaction tank 5. Then, after removing unwanted residues such as scum, in the improved oil statically-storing tank 6, a water-added fuel as a product is introduced into the product receiving tank 7.

The raw fuel oil improving tank 2 is a tank for subjecting raw fuel oil to pretreatment prior to the mixing. The raw fuel oil is supplied from another raw fuel oil tank 201. This raw fuel oil improving tank is intended to set the temperature of the raw fuel oil to a value appropriate to the mixing. The raw fuel oil is supplied from the raw fuel oil tank 201 to the raw fuel oil improving tank 2, and then heated and kept at a given temperature by a first heater 8 provided in the raw fuel oil improving tank 2 and controlled using a first thermocouple (T).

In order to improve temperature uniformity of the raw fuel oil, according to operation of a first pump 11, the raw fuel oil in the raw fuel oil improving tank 2 is extracted from the raw fuel oil improving tank 2, and re-input into the raw fuel oil improving tank via a header pipe 202. Further, the pretreatment may include fragmenting molecules of the raw fuel oil using a catalyst.

The refined water tank 3 performs a step of activating water. Preferably, water to be used in the method according to this embodiment is soft water. Thus, water is supplied from a water softening device 301. This refined water tank 3 is intended to keep the temperature of the water at a value appropriate to the mixing, and fragment molecules of the water to reach an active state. The water supplied to the refined water tank 3 is heated and kept at a given temperature by a second heater 8 provided in the refined water tank 3 and controlled using a second thermocouple (T). A level of activation can be measured using an ORP (Oxidation-Reduction Potential) meter. An ultrasonic wave generator 10 is provided at a bottom of the refined water tank 3. The ultrasonic wave generator 10 is operable to radiate an ultrasonic wave to the water to thereby fragment a molecular assembly of the water. In this process, it is desirable to alternately radiate two types of ultrasonic waves. Specifically, it is desirable to alternately radiate a first ultrasonic wave having a frequency of 10 kHz to 60 kHz and a second ultrasonic wave having a frequency of 200 kHz or more. This provides improved efficiency of the activation.

Further, in the refined water tank 3, tourmaline or a copper ion generating material may be used as a catalyst 9. During radiation of the ultrasonic wave from the ultrasonic wave generator 10, the catalyst 9 is kept in contact with the water, so that it is possible to improve efficiency of the activation by electrical energy radiated from the catalyst 9.

In order to uniformly activate the water, according to operation of a second pump 11, the water in the refined water tank 3 may be circulated such that it is extracted to a header 302 and returned to the refined water tank 3 via the header 302. In this case, the water is extracted from a lower portion of the refined water tank, and, after being pressurized by the second pump 11, re-injected from an upper portion of the refined water tank via the header pipe 302. The above structure makes it possible to achieve uniformity in temperature and activation of the water.

The activation of the water may be performed by plasma arc water treatment configured such that a discharge is generated between two electrodes connected to a high-voltage transformer to thereby cause dissociation and ionization of the water. In the case where the water is activated by the plasma arc water treatment, the plasma arc water treatment can be performed by a plasma arc water treatment unit provided in a circulation path of the water at a position between the refined water tank 3 and the second pump 11. Further, in the plasma arc water treatment, alumina is preferably used as the catalyst 9.

In the present invention, the application of electrical energy and the plasma arc water treatment will be collectively or generically referred to as “electrical stimulus”.

The reaction accelerator injection unit 4 is provided as a means to input an additive as a reaction accelerator into the refined water tank 3 or the refined water tank 3. The additive has an effect of decomposing hydrogen peroxide into hydrogen and oxygen, and releasing the oxygen to the atmosphere in the form of gas. As a result, it is possible to increase a hydrogen content ratio in a resulting water-added fuel so as to prevent lowering of the calorific value of the water-added fuel. As the additive, it is possible to use catalase, sodium hydroxide, an aqueous hydrogen peroxide solution or the like. The additive needs to be finely adjusted in terms of an input amount. In the case where catalase is added, an additive amount of catalase is preferably in the range of 0.04% to 0.05%, in terms of a ratio by weight thereof to the water. If the additive amount of catalase is less than 0.04%, it becomes impossible to sufficiently bring out an intended effect. On the other hand, if the additive amount is greater than 0.05%, it becomes impossible to ensure sufficient dissolution, leading to an increase in scum and thus deterioration in fuel quality.

The reaction tank 5 is provided as a means to perform a stirring and mixing step and a fusion step. The raw fuel oil is supplied from the raw fuel oil improving tank 2 to an upper portion of a reaction tank container 13. The water is supplied from the refined water tank 3 to a lateral side of the reaction tank container 13 via an injection pipe 14. According to operation of a third pump 11, a mixture of the raw fuel oil and the water is circulated such that it is extracted from a discharge port 15 of the reaction tank container 13, and re-input into the reaction tank container 13 via an OHR (Original Hydrodynamic Reaction) mixer 12 and the injection pipe 14. The OHR mixer 12 is capable of efficiently mixing a plurality of substances together. This reaction tank undergoes a pressure of about 3 to 9 atm during the fusion step, so that it needs to have a structure capable withstanding a higher pressure as compared to the remaining tanks. A third heater 8 is provided at a vertically intermediate position of the reaction tank. The mixture of the raw fuel oil and the water is controllably kept at a given temperature by the third heater 8.

The improved oil statically-storing tank 6 is a tank for temporarily storing produced substances after the fusion step. In this improved oil statically-storing tank, impurities generated from the additive and others, such as scum, are precipitated. A water-added fuel in which the raw fuel oil and the water are perfectly fused together, and the impurities, are separated from each other through static storage in the improved oil statically-storing tank 6, and the water-added fuel as a supernatant is supplied to the product receiving tank 7. The additive is included in the impurities, so that the impurities are returned to the reaction tank 5. A residence time in the improved oil statically-storing tank is preferably set to about one hour.

The product receiving tank 7 is a tank for storing the water-added fuel produced as a product. The produced water-added fuel is supplied from the product receiving tank 7 to a product storage tank 701, when it is accumulated to a certain amount.

The water-added fuel production method according to the one embodiment will be described below. This method comprises an activation step, an additive input step, a stirring and mixing step, a fusion step and a filtration step.

The activation step is performed using the refined water tank 3. This activation step is intended to fragment molecules of the water to reach an active state. By fragmenting molecules of the water to reach the active state, it becomes possible to improve compatibility with the raw fuel oil to thereby enable a larger amount of water to be used for producing a water-added fuel. Specifically, water is input into the refined water tank 3, and irradiated with an ultrasonic wave from the ultrasonic wave generator 10, so that the water is vibrated at a high frequency to promote molecular fragmentation. The molecular fragmentation of the water can be promoted by alternately radiating two types of ultrasonic waves each having a different frequency. For example, the two types of ultrasonic waves may have a frequency of 10 kHz to 60 kHz and a frequency of 200 kHz or more, respectively, to facilitate the molecular fragmentation. Further, tourmaline or a copper ion generating material serving as a catalyst is used in combination with the ultrasonic wave generator 10, to apply an electrical stimulus to the water. By operating the ultrasonic wave generator 10 while keeping such a catalytic material in contact with the water, it becomes possible to apply an electrical stimulus to the water to more effectively promote activation.

A level of activation by irradiation with the ultrasonic waves can be ascertained by measuring ORP (Oxidation-Reduction Potential) (my). An ORP value of the water to be obtained by irradiating it with the ultrasonic waves is preferably in the range of 160 mV to −200 mV. For reference the ORP value of normal tap water is in the range of 700 mV to 500 mV.

In addition, by irradiation with the ultrasonic waves, oxygen is released to improve the hydrogen content ratio.

For example, in the case where 200 L of water is brought into contact with tourmaline so as to reform the water, it is desirable to inject the water from a pipe having a nominal diameter of 15 A to 50 A at a flow rate of 20 L/min to 50 L/min While a reaction time may be suitably set to about one hour, the same activation effect can be obtained even when it is set in the range of 20 minutes to one day.

Next, the additive input step will be described. The additive input step is intended to add the additive stored in the reaction accelerator injection unit 4, to the refined water tank 3 or the reaction tank 5, to thereby increase a hydrogen content ratio in the water.

As the additive, it is possible to use one or more selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution. The additive needs to be finely adjusted in terms of an input amount. In case of using catalase, an additive amount of catalase is preferably in the range of 0.04% to 0.05%, in terms of a ratio by weight thereof to the water, as mentioned above. If the additive amount is less than 0.04%, it becomes impossible to sufficiently bring out an intended effect. On the other hand, if the additive amount is greater than 0.05%, it becomes impossible to ensure sufficient dissolution, leading to an increase in scum and thus deterioration in fuel quality.

As regards sodium hydroxide, the intended effect as the additive can be sufficiently brought out by an additive amount of 0.001 weight % to 0.1 weight %, with respect to 100 weight % of the water. As regards an aqueous hydrogen peroxide solution, the intended effect as the additive can be sufficiently brought out by an additive amount of 0.001 weight % to 0.1 weight %, with respect to 100 weight % of the water.

Next, the stirring and mixing step will be described. In the stirring and mixing step, the water after being activated in the refined water tank 3 and subjected to input of the additive is mixed with raw fuel oil. First of all, only raw fuel oil is input into the reaction tank 5. This raw fuel oil is circulated through the OHR mixer 12 of the reaction tank 5. By circulating the mixture to pass through the OHR mixer 12, molecules of the raw fuel oil are also homogenized, so that the raw fuel oil is more likely to be fused with the water. When the circulation is almost completed, the water is input from the refined water tank 3 into the reaction tank 5 little by little. This is intended to enable the water to be possibly homogeneously dispersed with respect to the raw fuel oil. The water supplied from the refined water tank 3 is pressurized by the second pump 11 of the refined water tank 3, and mixed with the raw fuel oil from the discharge port 15, and the resulting mixture is pressurized by the third pump 11 of the reaction tank 5, and further subjected to mixing by the OHR mixer 12. Preferably, the OHR mixer 12 is operated at a pressure (operating pressure) of 3 atm (0.3 MPa) or more and a temperature (operating temperature) of 40° C. to 80° C. Thus, respective pressures of the second and third pumps 11 of the refined water tank 3 and the reaction tank 5 are set in a manner suited to the pressure of the OHR mixer 12, and respective warming levels of the second and third heaters 8 of the refined water tank 3 and the reaction tank 5 are also set in a manner suited to the temperature of the OHR mixer 12. The water and the raw fuel oil mixed by the OHR mixer 12 are re-input from the injection pipe 14 into the reaction tank 5 via the header pipe 502. Efficiency and quality of the mixing varies depending on an angle of the injection pipe 14 with respect to the reaction tank 5, and a protruding amount of the injection pipe 14 toward an inside of the reaction tank 5.

For example, in the case where 100 L of the water is mixed with 100 L of the raw fuel oil, the mixture of the water and the raw fuel oil is preferably circulated through a pipe having a nominal diameter of 15 A to 50 A at a flow rate of 20 L/min to 50 L/min A mixing time may be set in the range of about 5 minutes to about 1 hour.

Next, the fusion step will be described. The fusion step is performed after completion of the input of the water from the refined water tank 3 into the reaction tank 5, and achieved by circulating the mixture through the OHR mixer 12. Preferably, the operating pressure and the operating temperature are set, respectively, to 3 atm (0.3 MPa) or more and in the range of 40° C. to 80° C., as with the stirring and mixing step. In this fusion step, by circulating the mixture to sufficiently pass through the OHR mixer 12, it is possible to promote fusion of the water and the raw fuel oil to produce a water-added fuel free from a risk of separation.

For example, in the case where 100 L of the water is fused with 100 L of the raw fuel oil, although the operating pressure and the operating temperature are preferably set, respectively, to 0.3 MPa (3 atm) or more and 70° C. or more, they may be set, respectively, to a higher pressure and a lower temperature, and it is most effective that the operating pressure and the operating temperature are set, respectively, to 0.9 MPa and 50° C. It is appropriate to ser a reaction time to fall within the range of 20 minutes to 60 minutes after reaching the above operating pressure and temperature.

Next, the filtration step will be described. The filtration step is intended to separate, from a finally produced water-added fuel, scum-like substances arising from solidification of components of an enzyme used during the production process, or other components. The technique using the improved oil statically-storing tank 6 is based on an idea of statically storing produced substances to separate them from each other based on a difference in specific gravity. Substances having relatively large specific gravities, such as scum, are accumulated on the bottom, and the water-added fuel having a relatively small specific gravity gathers as a supernatant layer. The water-added fuel as the supernatant layer is send to the product receiving tank 7 to accomplish a product. It is preferable to ensure a residence time of 1 hour or more in the improved oil statically-storing tank 6.

Alternatively, the produced substances may be enabled to pass through a filtration filter to separate scum or the like from the water-added fuel. As the filtration filter, it is possible to use a filtration filter having a pore size of about 10 to 30 μm. It is preferable to enable the produced substances to pass through the filtration filter at a temperature of 40° C. or less. Further, a passing speed (flow rate) is preferably set in the range of about 20 to 50 L/min when a pipe has a nominal diameter of 20 A to 50 A, and a lower passing speed is more preferable. The number of times of passing through the filtration filter may be one or more.

By performing the above steps in the above manner, it becomes possible to enable the water and the raw fuel oil to be perfectly mixed together without being separated from each other ever after the elapse of a certain time, and realize fusion of the water and the raw fuel oil within a relatively short period of time.

With reference to FIG. 3, the water-added fuel production apparatus according to the second embodiment will be described. In FIG. 3, the same element or component as that in the first embodiment is omitted. FIG. 3 is a diagram depicting the structure of an injection pipe for injection to a reaction tank in a water-added fuel production apparatus according to a second embodiment of the present invention. FIG. 3(a) is a top plan view for explaining a relationship between the reaction tank 5 and the injection pipe 14. FIG. 3(b) is a side view of the reaction tank 5.

In the first embodiment, the steps for the water-added fuel production have been described. Among them, it is important how to circulate the mixture of the water and the raw fuel oil in the stirring and mixing step and the fusion step. Basically, the circulation is performed, in the apparatus depicted in FIG. 2, by enabling the mixture discharged from the discharge port 15 of the reaction tank 5 to flow through the pump 11 and the OHR mixer 12, and to be re-input into the reaction tank 5 from the lateral side of the upper portion of the reaction tank 5 via the injection pipe 14 in the form of a jet flow. In the circulation, it is ideal that all of the mixture is evenly circulated. However, if a way to re-input into the reaction tank 5 is not adequate, only part of the mixture is circulated in a larger amount but the remaining part is not sufficiently circulated, leading to a problem that the entire mixture is not evenly formed as a water-added fuel, or it takes a lot of time for evenly forming the entire mixture as a water-added fuel.

Therefore, the inventor of the present invention made a study on the relationship between the reaction tank 5 and the injection pipe 14 for re-inputting the mixture into the reaction tank 5. As depicted in FIG. 3(b), in the second embodiment, a reaction tank 5 has a circular cylindrical upper portion, and a conical lower portion. As depicted in FIG. 3(a), four injection pipes 14 are attached to a lateral wall of the upper portion, and arranged so as to inject the mixture of the water and the raw fuel oil into the reaction tank 5 from four directions, respectively. An angle of a longitudinal direction of each of the injection pipes 14 with respect to a diametrical line of the cylindrical upper portion of the reaction tank 5 passing through a central axis of the cylindrical upper portion of the reaction tank 5 and an attached point at which the injection pipe 14 is attached to the cylindrical portion of the reaction tank 5 is defined as an attachment angle or injection direction of the injection pipe 14. Then, under conditions where the attachment angle is changed in the range of 0 degree to 90 degrees, a time required for fusion, and quality of a resulting water-added fuel, were checked. In FIG. 3(c), an injection pipe 14 a 1 is attached such that the attachment angle becomes 0 degree. Similarly, injection pipes 14 a 2, 14 a 3, 14 a 4 are attached while an angle with respect to an axis of the injection pipe 14 a 1 is gradually increased. The angle was increased at angular intervals of 15 degrees. As a result, it was ascertained that, when the angle with respect to the axis is 45 degrees, the time required for fusion is minimized, and a resulting water-added fuel has good quality. This result shows that the attachment angle of each of the injection pipes 14 is preferable set in the range of about 40 to 50 degrees with respect to the diametrical line.

Further, a protruding amount of each of the injection pipes 14 toward an inside of a reaction tank 5 having a diameter of 60 cm, as depicted in FIG. 3(d), a time required for fusion, and quality of a resulting water-added fuel, were checked. In FIG. 3(d), an injection pipe 14 b 1 is attached such that the protruding amount becomes 0. Similarly, injection pipes 14 b 2, 14 b 3, 14 b 4 are attached while the protruding amount is gradually increased. The protruding amount was increased in increments of 10 cm. As a result, it was ascertained that, when the protruding amount is 10 cm, the time required for fusion is minimized, and a resulting water-added fuel has good quality. Further, in case of using a reaction tank having a larger size, it is preferable to increase the protruding amount of the injection pipe, and/or increase the number of injection pipes, according to the diameter of the reaction tank.

Considering the above, for the input of the mixture from the injection pipe 14 into the reaction tank 5, the attachment angle with respect to the diametrical line of the cylindrical portion is optimally set to 45 degrees, and the protruding amount of the injection pipe 14 toward the inside of the reaction tank 5 is optimally set to 10 cm. By attaching the injection pipe at a given angle with respect to the diametrical line of the cylindrical portion, it becomes possible to create a natural vortex within the reaction tank. This also makes it possible to effectively perform the mixing. Further, by setting the protruding amount of the injection pipe 14 toward the inside of the reaction tank 5 to a given amount, it becomes possible to avoid a situation where the circulated mixture gathers only around an outer peripheral region or a central region of the mixture in the reaction tank 5. The injection pipe 14 is disposed at a position upwardly away from a liquid surface in the reaction tank 5, preferably by at least 8 cm, more preferably by at least 10 cm, and preferably configured to inject the mixture therefrom at a high speed.

By adjusting the arrangement of the injection pipe 14 with respect to the reaction tank 5 in the above manner, it becomes possible to enable the water and the raw fuel oil to be perfectly mixed together without being separated from each other ever after the elapse of a certain time, and realize fusion of the water and the raw fuel oil within a relatively short period of time.

With reference to FIG. 4, a water-added fuel production apparatus according to a third embodiment of the present invention will be described below.

FIG. 4 is a schematic diagram depicting one example of a plasma arc water treatment unit usable as a water activation device in the water-added fuel production apparatus according to the third embodiment. This plasma arc water treatment unit 20 comprises a first electrode 21 (indicated by the hexagonal dotted-line in FIG. 4) disposed in a central region of the device, and a plurality of (in FIG. 4, twelve) second electrodes 22 arranged to surround the first, central, electrode 21, wherein the first and second electrodes 21, 22 are connected to a high-voltage transformer (not depicted). Upon supplying electric power to the first and second electrodes, an arc discharge is generated between the first and second electrodes. In the production apparatus 1 depicted in FIG. 2, the plasma arc water treatment unit 20 is installed between the refined water tank 3 and the second pump 11, and the water from the refined water tank is sent to pass through the plasma arc water treatment unit 20, so that it becomes possible to activate water by plasma arc water treatment. Preferred examples of the plasma arc water treatment unit may include a plasma arc water treatment unit used in Ultra U-MAN manufactured by Nippon Risuiken, K.K.

EXAMPLE Example 1

A water-added fuel using A-heavy oil as raw fuel oil was produced in the following manner.

First of all, 3 kg of tourmaline (tourmaline ore (small size) purchased from New Wave SA, who directly imported it from a mine in Estado de Tocantins, Brazil), and 20 L of tap water were put in a 25 L container provided with a section for housing tourmaline, an ultrasonic wave generator (35 kHz ultrasonic transducer) and a temperature gauge and connected to a circulation pump (24 L/min×0.5 MPa). 20 mL of catalase (Leonet F-35 manufactured by Nagase ChemteX Corporation) was added to the water. Then, the ultrasonic transducer was activated, and the circulation pump was activated to start circulation of the water. A preset temperature of a 3 kW line heater provided in a circulation path of the water was set to 40° C., and the circulation was continued for one hour after confirmation of the fact that the temperature of the water in the container has reached 40° C. or more. After the elapse of one hour, the oxidation-reduction potential of the water in the container was measured by an ORP meter. As a result, it was 12 mV.

Then, 20 L of commercially-available A-heavy oil (Class 1 (A), No. 1 heavy oil purchased from Fuji Kosan Co., Ltd.) was put in a 25 L container provided with a temperature gauge and connected to a circulation pump as with the aforementioned container. The circulation pump was activated to start circulation of the A-heavy oil. A preset temperature of a 3 kW line heater provided in a circulation path of the A-heavy oil was set to 40° C., and the circulation was continued for one hour after confirmation of the fact that the temperature of the A-heave oil in the container has reached 40° C. or more.

The water and the A-heavy oil activated in the above manner were mixed and stirred, and a resulting mixture was further fused together by applying heat and pressure thereto, in the following manner. 10 L of the activated water and 10 L of the obtained A-heavy oil were put in a 25 L, open-type container having an upper portion opened to the atmosphere, wherein the container was provided with a 1 kW warming heater and a propeller-type stirrer, in addition to a temperature gauge, and connected to a circulation pump and a blending mixer (OHR (Original Hydrodynamic Reaction) mixer manufactured by OHR Laboratory Corporation). The warming heater was powered on to enable the temperature of the liquid in the container to be maintained at 40° C. 10 mL of the same catalase as described above was added thereto. After the elapse of 40 minutes, the stirrer was powdered on, to mix and stir the water and the A-heavy oil. Then, the circulation pump was activated and adjusted such that a supply pressure to the blending mixer becomes about 0.5 MPa, to circulate the mixed liquid. A circulation pipe for allowing the liquid to be input from the circulation path into the container therethrough in the above process was disposed at a position upwardly away from a surface of the mixed liquid in the container by about 8 cm. After circulating the mixed liquid for one hour, the stirrer, the circulation pump and the warming heater were deactivated. A liquid (water-added fuel) obtained in the above manner was statically stored for about three days, and an analytical sampler was collected therefrom. An amount of the collected sample was 20 L.

Example 2

Except that commercially-available light oil (No. 2 light oil purchased from JX Nippon Oil & Energy Corporation (ENEOS)) was used as raw fuel oil, in place of the A-heavy oil, a water-added fuel was produced in the same manner as that in Example 1, and an analytical sampler was collected therefrom. An amount of the collected sample was 20 L.

Table 1 presents a result of componential analysis of the two types of water-added fuels produced in Example 1 and Example 2 of the present invention. Each of the water-added fuels is obtained by mixing and fusing the water and the raw fuel oil together at a ratio of 1:1.

For comparison, each of the A-heavy oil and the light oil used as raw fuel oil was subjected to the same componential analysis

First of all, looking at gross calorific value and net calorific value, each of Example 1 and Example 2 is superior to the raw fuel oil, which shows that the intended effect of the present invention is brought out.

Secondly, looking at water content, in each of Example 1 and Example 2, the volume % of the water content is 0.00%. In each of Example 1 and Example 2, the water-added fuel was obtained by mixing and fusing the water and the raw fuel oil together at a ratio of 1:1. Thus, if sufficient fusion is not achieved, a certain volume of water should be detected. That is, the fact that the volume % of the water content is 0.00% means that the raw fuel oil and the water were perfectly fused, and thereby no water component was analytically detected.

As above, the present invention makes it possible to perfectly fuse the raw fuel oil and the water, and produce a high-quality water-added fuel.

TABLE 1 Test Result Testing Test Items Unit Example 1 Example 2 Method Gross calorific J/g 45,450 45,880 JIS K2279 value Net calorific J/g 42,440 42,690 JIS K2279 value Density (15° C.) g/cm³ 0.8445 0.8283 JIS K2249-1 C (carbon mass % 86.6 85.8 Elemental content) analyzer H (hydrogen mass % 13.3 14.1 Elemental content) analyzer S (sulfur content) mass % 0.045 0.0000 JIS K2541-6 N (nitrogen mass % 0.0043 0.0003 JIS K2609 content) H₂O (water) mass % 0.00 0.00 JIS K2275 Flash point ° C. 73.0 73.0 JIS K2265-3 Kinetic viscosity mm²/s 2.417 3.498 JIS K2283 (50° C.) Pour point ° C. −15.0 −10.0 JIS K2269 Carbon residue mass % 0.01 0.01 JIS K2270-2 content Water content volume % 0.00 0.00 JIS K2275 Ash content mass % 0.000 0.000 JIS K2272 Sulfur content mass % 0.045 0.0009 JIS K2541-6 Inorganic acid — neutral neutral JIS K2252

Example 3

A water-added fuel was produced using the apparatus depicted in FIGS. 2 and 3 and using light oil as raw fuel oil.

First of all, 150 L of tap water was poured into the refined water container provided with the section for housing tourmaline, where in the section was charged with the same tourmaline as that used in Example 1. The second heater installed in the refined water tank was powered on, and a preset temperature thereof was set to 40° C. 150 mL of the same catalase as that used in Example 1 was added thereto. The second circulation pump connected to the refined water tank was activated (discharge pressure: 0.5 MPa), and the ultrasonic wave generator installed in the refined water tank was activated radiate an ultrasonic wave (frequency: 40 kHz) for 60 minutes until the temperature of the water reaches 40° C., and additionally for 60 minutes after the temperature reached 40° C. In operation of inputting the water into the refined water tank, only one of the four injection pipes was used (the remaining three injection pipes were closed), and a flow rate at a distal end of the injection pipe was set to 3.3 m/s. The oxidation-reduction potential of the resulting water was measured by an ORP meter. As a result, it was 20 mV.

Then, 150 L of commercially-available light oil (No. 2 light oil purchased from JX Nippon Oil & Energy Corporation (ENEOS)) was poured into the raw fuel oil improving tank. The first heater installed in the raw fuel oil improving tank was powered on, and a preset temperature thereof was set to 40° C. The first circulation pump connected to the raw fuel oil improving tank was activated (discharge pressure: 0.3 MPa) to circulate the light oil for 60 minutes until the temperature of the light oil reaches 40° C., and additionally for 60 minutes after the temperature reached 40° C. In operation of injecting the light oil into the raw fuel oil improving tank, only one of the four injection pipes was used (the remaining three injection pipes were closed), and a flow rate at a distal end of the injection pipe was set to 2.0 m/s.

The water and the light oil activated in the above manner were mixed and stirred, and a resulting mixture was further fused together by applying heat and pressure thereto, in the following manner. Specifically, 75 L of the light oil in the raw fuel oil improving tank and 55 L of the activated water in the refined water tank were transferred to the reaction tank (added water rate: 42%). 62 mL of the same catalase as described above was added thereto. The third heater was powered on, to enable the temperature of the liquid in the container to become 40° C. After the temperature of the liquid reached 40° C., the third circulation pump was activated and adjusted such that a supply pressure to the blending mixer becomes about 0.5 MPa, to circulate the mixed liquid for 60 minutes. In operation of inputting the mixed liquid into the reaction tank, only one of the four injection pipes was selected and used (the remaining three injection pipes were closed), and a flow rate at a distal end of the selected injection pipe was set to 2.0 m/s. Further, the selected injection pipe was attached in such a manner as to be kept from submerging in the mixed liquid in the reaction tank. Specifically, the selected injection pipe was disposed at a position upwardly away from a surface of the mixed liquid in the reaction tank by about 8 cm. An analytical sampler was collected from the resulting liquid. An amount of the collected sample was 114 L.

Example 4

Except that temperatures of the refined water tank, the raw fuel oil improving tank and the reaction tank were set, respectively, to higher values: 42° C., 41° C. and 44° C., and a circulation time in the refined water tank and the raw fuel oil improving tank was set to one-half that in Example 3 (specifically, set to 60 minutes in each of the tanks), a water-added fuel was produced in the same manner as that in Example 3. The oxidation-reduction potential of the water obtained in the refined water tank was measured by an ORP meter. As a result, it was 26 mV. An analytical sampler was collected from a liquid obtained in the reaction tank. An amount of the collected sample was 114 L.

Example 5

Except that: the A-heavy oil (Class 1 (A), No. 1 heavy oil purchased from Fuji Kosan Co., Ltd.) was used as raw fuel oil; the temperature of the reaction tank was set to 36° C.; the circulation time in each of the refined water tank and the raw fuel oil improving tank was set to 90 minutes; and the additive amount of catalase was set to 230 mL and 130 mL, respectively, for the refined water tank and the reaction tank, a water-added fuel was produced in the same manner as that in Example 3. The oxidation-reduction potential of the water obtained in the refined water tank was measured by an ORP meter. As a result, it was 18 mV. An analytical sampler was collected from a liquid obtained in the reaction tank. An amount of the collected sample was 114 L.

Table 2 presents a result of componential analysis of the two types of water-added fuels produced in Example 4 and Example 5 of the present invention.

TABLE 2 Test Result Test Items Unit Example 4 Example 5 Testing Method Gross calorific value J/g 45,950 44,400 JIS K2279 Net calorific value J/g 42,740 41,640 JIS K2279 Density (15° C.) g/cm³ 0.8277 0.8760 JIS K2249-1 C (carbon content) mass % 85.7 87.7 Elemental analyzer H (hydrogen content) mass % 14.2 12.2 Elemental analyzer S (sulfur content) mass % 0.0008 0.51 JIS K2541-6 N (nitrogen content) mass % 0.0002 0.033 JIS K2609 H₂O (water) mass % 0.00 0.00 JIS K2275 Flash point ° C. 64.5 78.5 JIS K2265-3 Kinetic viscosity (50° C.) mm²/s 3.558 2.480 JIS K2283 Pour point ° C. −12.5 −22.5 JIS K2269 Carbon residue content mass % 0.01 0.05 JIS K2270-2 Water content volume % 0.00 0.00 JIS K2275 Ash content mass % less than 0.004 JIS K2272 0.001 Sulfur content mass % 0.0008 0.51 JIS K2541-6 Inorganic acid — neutral neutral JIS K2252

[Qualitative Analysis of Water-Added Fuel]

The sample of the water-added fuel obtained by the method according to the present invention using light oil as raw fuel oil in Example 3 was subjected to qualitative analysis based on gas chromatogram-mass spectrometry (GC-MS). An analytical sample was prepared by diluting the sample obtained in Example 3, with n-hexane 1000 times. HP-5MS (length: 30 m, inner diameter: 2.5 mm, membrane thickness: 0.25 μm) was used as a gas chromatography column, and He was used as carrier gas. An injection amount of the analytical sample was set to 1 μL, and an injection mode was set to the splitless mode. An oven temperature was held at 50° C. for 3 minutes, and then after being from 50° C. to 100° C. at a temperature rising speed of 5° C./min, and from 100° C. to 300° C. at a temperature rising speed of 15° C./min, held at 300° C. for 3 minutes. A GC-MS chart obtained as a result of the analysis is depicted in FIG. 5, wherein FIG. 5(a) is a TIC chromatogram, and FIG. 5(b) is a mass spectyrum indicating peaks at about 18.4 min.

As to the sample of the water-added fuel obtained in Example 4 was also subjected to the same qualitative analysis. A result of the analysis is presented in FIG. 6.

Further, for comparison, the light oil used as raw fluid oil was subjected to the same qualitative analysis. A result of the analysis is presented in FIG. 7.

Comparing FIGS. 5, 6 and 7 with each other, it could be ascertained that a component composition of each of the water-added fuels obtained in Examples 3 and 4 is well coincident with that of the raw fuel oil, although components having relatively large carbon numbers (larger than C19) tend to decrease as compared to the raw fuel oil.

The sample of the water-added fuel obtained by the method according to the present invention using A-heavy oil as raw fuel oil in Example 5 was also subjected to the same qualitative analysis. A result of the analysis is presented in FIG. 8.

Further, for comparison, the A-heavy oil used as raw fluid oil was subjected to the same qualitative analysis. A result of the analysis is presented in FIG. 9.

Comparing FIGS. 8 and 9 with each other, it could be ascertained that a component composition of the water-added fuel obtained in Example 5 is well coincident with that of the raw fuel oil.

[Properties Test of Water-Added Fuel]

The samples of the water-added fuels obtained by the method according to the present invention using light oil as raw fuel oil in Examples 3 and 4 were subjected to properties test. Items and methods of the properties test were as follows.

-   -   Density (vibration type, 15° C.): JIS K2249     -   Kinetic viscosity (30°): JIS K2283     -   Nitrogen quantitative analysis: JIS K2609     -   Sulfur content (UV fluorescence method): JIS K2541-6     -   Oxygen content: ASTM D5622     -   Light oil composition analysis (JPI method); JPI-5S-49

Further, for comparison, the light oil used as raw fluid oil was subjected to the same properties test.

A result of the analysis is presented in Table 3.

From Table 3, it is observed that the water-added fuels obtained by the method according to the present invention is reduced in terms of an aromatic content, and is increased in terms of a content of saturable components. It is considered that light oil having a relatively small aromatic content and a relatively large content of saturable components is desirable in view of combustion efficiency, and reduction of toxic content in exhaust gas including PM.

TABLE 3 Test Result Raw fuel oil Test Items Unit Example 3 Example 4 (light oil) Density (15° C.) g/cm³ 0.8297 0.8279 0.8293 Kinetic viscosity mm²/s 2.976 3.565 3.377 (30° C.) Nitrogen quantitative ppm 2 1 2 analysis Sulfur content ppm 8 9 9 Oxygen content mass % <0.1 <0.1 <0.1 Componential volume % 80.7 80.2 76.1 Analysis (JPI method) Content of saturable components Olefin content volume % 0.0 0.0 0.0 Monoaromatic content volume % 18.4 18.0 19.9 Bicyclic aromatic volume % 0.6 1.6 3.6 content Tricyclic aromatic volume % 0.3 0.2 0.4 content

[Oxidative Stability Test of Water-Added Fuel]

The samples of the water-added fuels obtained by the method according to the present invention using light oil as raw fuel oil in Examples 3 and 4 were subjected to oxidative stability test (test method: ASTM D2274). Further, for comparison, the light oil used as raw fluid oil was subjected to the same oxidative stability test.

In each of the samples, an amount of sludge measured was lower than 0.1 mg/100 mL as a measurement limit.

[Driving Test Using Water-Added Fuel]

The sample of the water-added fuel obtained by the method according to the present invention using light oil as raw fuel oil in Example 3 was subjected to the JC08 mode driving test (vehicle used: Nissan NV350, LDF-VW2E26, Vehicle mass: 1840 kg). Further, for comparison, commercially-available light oil (JIS No. 2) was subjected to the same driving test.

A result of the driving test is presented in Table 4. For reference, the exhaust emission control values are put down therewith.

From Table 4, attention is focus on the point that the water-added fuel obtained by the method according to the present invention is low, particularly, in terms of CO2 emission, as compared to the commercially-available light oil.

42% by volume of the water-added fuel obtained in Example 3 is derived from water. From previous experimental results, a conversion ratio of the water mixed with the raw fuel oil and converted to fuel is assumed to be about 70%, and a volume ratio of a water-derived fuel to a total amount of produced fuel can be calculated by the following formula: [volume ratio of water-derived fuel]=(42×0.7)/(58+42×0.7)=34%. From this result, in Example 3, it can be evaluated that 34% of the obtained fuel is not derived from petroleum. Therefore, the fuel obtained in Example 3 can be deemed to reduce the carbon emission amount by about 34%.

TABLE 4 Test Result Exhaust Emission Test Items Unit Example 3 Light Oil Control Values Fuel Economy (FE) km/L 13.15 12.71 12.4 T-HC g/km 0.001 0.001 0.032 CO g/km 0.004 0.005 0.84 NOx g/km 0.182 0.185 0.20 PM g/km 0.001 0.001 0.009 CO₂ g/km 200.1 207.0 216.0

LIST OF REFERENCE SIGNS

-   1: water-added fuel production apparatus -   2: raw fuel oil improving tank -   3: refined water tank -   4: reaction accelerator injection unit -   5: reaction tank -   6: improved oil statically-storing tank -   7: product receiving tank -   8: heater -   9: catalyst -   10: ultrasonic wave generator -   11: pump -   12: OHR mixer -   13: reaction tank container -   14: injection pipe -   15: discharge port -   20: plasma arc water treatment unit -   21, 22: electrode 

1. A method for producing a water-added fuel by mixing fuel oil and water together, the method comprising at least: a water activation step of applying an electrical stimulus to water to thereby activate the water; an additive input step of, before, during or after the water activation step, adding, as an additive, at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution, to the water; a stirring and mixing step of mixing the water after undergoing the water activation step and the additive input step, with raw fuel oil, and stirring the resulting mixture; and a fusion step of fusing the raw fuel oil and the water after undergoing the stirring and mixing step, together under a high temperature and a high pressure, wherein the water-added fuel is substantially free of water (H₂O) and has a composition substantially equal to or approximate to that of the raw fuel oil.
 2. The method as recited in claim 1, wherein a mixing ratio by volume of the water to the raw fuel oil is about 1 or less with respect of 1 of the raw fuel oil.
 3. The method as recited in claim 2, wherein the stirring and mixing step includes: inputting only the raw fuel oil into a stirring and mixing tank; and then injecting the water after undergoing the water activation step and the additive input step, onto a surface of the raw fuel oil little by little, while stirring the raw fuel oil, to create strong waves on the oil surface to thereby enable the water to be added to and mixed with the raw fuel oil.
 4. The method as recited in claim 3, wherein the stirring and mixing tank to be used for stirring in the stirring and mixing step comprises a cylindrical portion, and at least one injection pipe for inputting the water after undergoing the water activation step and the additive input step, into the stirring and mixing tank, in the form of a jet flow, and wherein an injection direction of the water from the injection pipe is set to have an angle of about 40 degrees to about 50 degrees with respect to a diametrical line of the cylindrical portion passing through a central axis of the cylindrical portion and an attached point at which the injection pipe is attached to the cylindrical portion.
 5. The method as recited in claim 4, wherein the stirring and mixing tank is provided with a plurality of the injection pipes, and wherein each of the injection pipes is disposed in a same manner in terms of the angle with respect to the diametrical line of the cylindrical portion passing through the central axis of the cylindrical portion and the attached point at which the injection pipe is attached to the cylindrical portion.
 6. The method as recited in claim 4, wherein the injection direction of the water from the injection pipe is about 45 degrees with respect to the diametrical line.
 7. The method as recited in claim 4, wherein the injection pipe has a protruding portion protruding inside the stirring and mixing tank.
 8. The method as recited in claim 7, wherein the protruding portion has a length of about 10 cm, wherein an injection port of the protruding portion is disposed at a position upwardly away from a liquid surface in the stirring and mixing tank by at least about 8 cm.
 9. The method as recited in claim 1, wherein the additive input step includes adding catalase in a ratio by weight thereof to the water of 0.04 to 0.05%.
 10. The method as recited in claim 1, wherein the water activation step includes activating the water such that an ORP value thereof falls within the range of 160 mV to-200 mV.
 11. The method as recited in claim 1, wherein the water activation step includes irradiating the water alternately with first and second ultrasonic waves each having a respective one of a frequency of 10 kHz to 60 kHz and a frequency of 200 kHz or more, while keeping tourmaline or a copper ion generating material in contact with the water.
 12. The method as recited in claim 1, wherein the fusion step is performed under a pressurization condition set at about 0.3 Mpa or more and a heating condition set in the range of about 40° C. to about 80° C.
 13. The method as recited in claim 1, wherein the stirring and mixing step is performed using an OHR (Original Hydrodynamic Reaction) mixer.
 14. An apparatus for producing a water-added fuel by mixing fuel oil and water together, the apparatus comprising: a water activation device for applying an electrical stimulus to water to thereby activate the water; an additive input device for adding, as an additive, at least one selected from the group consisting of catalase, sodium hydroxide and an aqueous hydrogen peroxide solution, to the water; a stirring and mixing device for mixing the water after passing through the water activation device and the additive input device, with raw fuel oil, and stirring the resulting mixture; and a fusion device for fusing the raw fuel oil and the water after passing through the stirring and mixing device, together under a high temperature and a high pressure.
 15. The apparatus as recited in claim 14, wherein the water activation device comprises an ultrasonic generator.
 16. The apparatus as recited in claim 15, wherein the water activation device comprises a section for housing a catalyst, and wherein the catalyst is tourmaline.
 17. The apparatus as recited in claim 14, wherein the water activation device comprises a plasma-arc water treatment unit.
 18. The apparatus as recited in claim 17, wherein the water activation device comprises a section for housing a catalyst, and wherein the catalyst is aluminum.
 19. The apparatus as recited in claim 14, wherein the stirring and mixing device comprises an open-type stirring and mixing tank opened to the atmosphere.
 20. The apparatus as recited in claim 19, wherein the stirring and mixing device comprises an injection pipe for inputting a liquid to be stirred and mixed, into the stirring and mixing tank, in the form of a jet flow, and wherein the injection pipe is disposed at a position upwardly away from a liquid surface in the stirring and mixing tank by at least about 8 cm.
 21. The apparatus as recited in claim 14, wherein the fusion device comprises an OHR (Original Hydrodynamic Reaction) mixer. 